Public Health Officials Press Congress to Fund Zika Battle

Experts cite new evidence linking virus and brain defects

WASHINGTON -- The government's leading public health officials urged Congress to boost funding for the Zika virus and announced new evidence linking the mosquito-borne illness to major birth defects at a hearing on Wednesday.

The Obama administration requested $1.8 billion from Congress in emergency funding to respond to the Zika virus on Monday.

"There's the enemy," said Thomas Frieden, MD, MPH, director of the Centers for Disease Control and Prevention, flashing on screen an enlarged image of a winged insect perching on what appears to be human skin.

"The Aedes aegypti mosquito is a very challenging, what we call, disease vector to control," he continued.

These unrelenting pests are daytime feeders that gorge on four to five people in one "blood meal." They can virtually disappear -- under tables and inside closets -- and their larva can survive droughts, Frieden said.

The Zika virus, identified in 1947, was for a long while thought to be only a nuisance. Only about one in five infected people experience symptoms, which are generally mild -- they include fever, joint pain, and sometimes rashes. However, its recent emergence in Central and South America and overlap with a spike in microcephaly cases -- a serious birth defect characterized by abnormally small brain growth -- has sparked greater respect and fear for the illness.

Brazil reported more than 4,000 cases of microcephaly cases potentially related to the virus as of October 2015, according to Rep. Jeff Duncan (R-S.C.) but only a small fraction of those cases were confirmed.

However, Frieden revealed that the latest study of four infants who died of microcephaly -- either in the womb or within a day of their birth -- from CDC researchers and their Brazilian counterparts, uncovered genetic material from the Zika virus in two of the infants.

"This is the strongest evidence to date that Zika is the cause of microcephaly," Frieden said.

"But it's still not definitive," he added.

Frieden said more analysis of clinical and epidemiological patterns is needed to validate the link.

"We're working around the clock to find out as much as we can, as quickly as we can, to inform the public and to do everything that we can do to reduce the risk to pregnant women."

Frieden acknowledged this, even addressing several key unknowns that the CDC and other partners are trying to resolve:

Whether nutrition and other infections contribute to the development of microcephaly

Whether maternal to child transmission of the virus can occur at any time in a pregnancy or only at certain stages

Whether symptomatic Zika is more likely to cause other adverse health outcomes then asymptomatic Zika

How long the virus can persist in semen and whether infected men can spread the virus to sexual partners

Frieden also highlighted the need for better diagnostics. Because the virus persists in the blood for only a short period, determining if someone has Zika a couple of months or even a couple of weeks later is "very complex."

Meanwhile, the CDC is also optimizing its efforts to track and eliminate the "enemy" mosquitoes. This requires adequate surveillance systems and targeted use of the right insecticides.

"You need a vector control or mosquito control system to track where the mosquitoes are and respond in real time when problems emerge," Frieden said.

The CDC has also developed basic tests to determine insecticide resistance and is weighing the possibility of genetic manipulation -- an approach challenged by both "scalability and community acceptance," Frieden said.

Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases (NIAID) for the National Institutes of Health who also spoke at the hearing, said his agency's task is to focus on basic clinical and biomedical research that can be harnessed to develop countermeasures such as diagnostics and vaccines.

When asked how soon a vaccine might be available, Fauci said, "You could conceivably have it by the end of 2017," but he described such as timeline as "rocket speed" in terms of development and approvals.

While Fauci noted difficulties in finding drug manufacturers to produce a West Nile virus vaccine, he said he was confident "we won't have this problem with Zika."

Since mother to child transmission of the disease is of greatest concern, getting that treatment to child-bearing women in target countries would be critical, he stressed.

Also in the vein of prevention, Rep. Ami Bera, MD, (D-Calif.) stressed the importance of providing access to contraception for women in Zika-affected areas.

"This isn't about abortion or not abortion. This is about making sure that those women who are not planning on getting pregnant have the ability to prevent that pregnancy until we get a better understanding of what we're dealing with."

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